Breastfeeding and no period? pregnancy?

Hey Mamas, quick question for those mamas who don't have a regular period while breastfeeding: what do you do as far as making sure you're not pregnant again? My hubby and I use the pull out method 90+% of the time. We are not actively TTC. We have a date night 1-2 nights per week where we will have a couple drinks. I don't want to be surprised and be pregnant and then consume alcohol. I also don't want to take a pregnancy test twice a week! How do you all manage when you don't have AF?